Solar cell, cell module and photovoltaic system

Abstract

The invention is applicable to the field of photovoltaic technology, and provides a solar cell, a cell module and a photovoltaic system, the solar cell comprising: a silicon substrate comprising a doped layer; the edge main grid is arranged at the edge position of the silicon substrate and extends along the first direction; the edge Pad points are arranged corresponding to the edge main grids; the connecting wire group comprises a connecting conductor and a fine grid line, the connecting conductor is in non-physical contact with the doping layer and is connected with the edge main grid and the edge Pad point, the connecting conductor extends along a second direction, and the second direction is intersected with the first direction; the connecting conductor forms a hollow groove, and the fine grid line is erected at the hollow groove and is in physical contact with the doping layer. The thin grid lines collect current carriers generated by the doping layer, current carrier loss caused by shielding of the connecting conductor is reduced, meanwhile, the thin grid lines and the connecting conductor are only in contact at the two ends of the thin grid lines, the contact area is small, current carrier recombination loss caused by slurry recombination can be reduced, slurry used in the manufacturing process can be saved, and the manufacturing cost is reduced. Therefore, the production cost of the solar cell is reduced.

Description

Technical Field

[0001] The invention belongs to the field of photovoltaic technology, and in particular relates to a solar cell, a cell assembly and a photovoltaic system. Background Art

[0002] As an efficient and clean energy conversion device, solar cells are widely used in various photovoltaic power generation systems. In the traditional solar cell structure, main grid lines, fine grid lines and pad points are usually set on the surface of the cell to collect and transmit current. The main grid lines extend along one side of the cell surface, and the fine grid lines are perpendicular to the main grid lines, contacting the doped layer of the cell to collect photogenerated carriers.

[0003] Usually, a thicker connecting grid is set between the pad point and the main grid. The thicker connecting grid causes part of the battery surface area to be blocked, thereby reducing the illuminated area and affecting the photoelectric conversion efficiency. Secondly, because the connecting grid is thicker and the contact area with the main grid line is larger, it is easy to produce slurry recombination at the contact point, causing the carriers to be recombined before reaching the electrode, reducing the performance of the battery. In addition, the large-scale use of fine grid slurry not only increases the cost, but may also introduce additional defects and losses due to the uneven distribution of the slurry. Summary of the invention

[0004] The present invention provides a solar cell, a cell assembly and a photovoltaic system, aiming to solve the problems that the traditional arrangement method affects the photoelectric conversion efficiency, is prone to compounding and has high production costs.

[0005] The present invention is achieved in that a solar cell comprises:

[0006] a silicon substrate including a doped layer;

[0007] An edge main gate is arranged at an edge position of the silicon substrate and extends along a first direction;

[0008] Edge Pad points, arranged corresponding to the edge main grid;

[0009] A connection line group, comprising a connection conductor and a thin gate line, wherein the connection conductor is not in physical contact with the doped layer and is used to connect the edge main gate and the edge pad point, and the connection conductor extends along a second direction, and the second direction intersects the first direction;

[0010] The connecting conductor forms at least one hollow groove, the fine gate line is arranged at the hollow groove, and the fine gate line is in physical contact with the doping layer.

[0011] Optionally, at least one thin grid line is arranged at each of the hollow grooves.

[0012] Optionally, the thin gate lines extend along the second direction.

[0013] Optionally, along the second direction, the total length of the thin gate lines is 10% to 90% of the total length of the connecting conductors.

[0014] Optionally, along the second direction, the total length of the thin grid lines is 50% to 90% of the total length of the connecting conductors.

[0015] Optionally, at least one hollow groove is provided, and the hollow groove extends along the second direction.

[0016] Optionally, a plurality of hollow grooves are provided.

[0017] Optionally, along the second direction, the hollow grooves are arranged along the same straight line.

[0018] Optionally, along the second direction, at least some of the hollow grooves are arranged in a staggered manner.

[0019] Optionally, along the second direction, distances between adjacent hollow grooves are equal.

[0020] Optionally, along the second direction, distances between at least some adjacent hollow grooves are unequal.

[0021] Optionally, the hollow groove is at least one of a rectangular, circular, trapezoidal, triangular, fan-shaped, and elliptical shape.

[0022] Optionally, along the second direction, the fine gates are collinear.

[0023] Optionally, along the second direction, at least some of the fine grids are staggered.

[0024] Optionally, along the second direction, at least one of the thin grid lines is placed at a central position of the hollow groove.

[0025] Optionally, along the second direction, at least one of the thin grid lines is placed at an edge of the hollow groove.

[0026] Optionally, the width of the connecting conductor is 100-400 μm.

[0027] Optionally, the width of the connecting conductor is 200-300 μm.

[0028] Optionally, the edge main grid includes a connection portion in contact with the connection conductor and extension portions extending along two ends of the connection portion, and a width of the connection conductor is 1 to 5 times a width of the connection portion.

[0029] Optionally, the width of the connecting conductor is 1 to 3 times the width of the connecting portion.

[0030] Optionally, the edge main grid includes a connecting portion in contact with the connecting conductor and extended portions extending along two ends of the connecting portion, and a cross-sectional area of ​​the connecting conductor is 1 to 5 times a cross-sectional area of ​​the connecting portion.

[0031] Optionally, the cross-sectional area of ​​the connecting conductor is 1 to 3 times the cross-sectional area of ​​the connecting portion.

[0032] Optionally, a plurality of first fine gates and a plurality of second fine gates are alternately arranged along the first direction on the silicon substrate, the edge main gate and the edge Pad point are respectively set on the two opposite edges of the silicon substrate, the first fine gate is connected to the edge main gate and the edge Pad point on one side, and the second fine gate is connected to the edge main gate and the edge Pad point on the other side, wherein the first fine gate and the second fine gate have different properties.

[0033] Optionally, first regions and second regions are alternately arranged on the silicon substrate along the first direction, and the first regions and the second regions have different polarities;

[0034] The first fine gate is disposed in the first region, and the second fine gate is disposed in the second region.

[0035] Optionally, the connecting conductor is a copper conductor or an aluminum conductor, and the fine grid wire is a silver fine grid wire.

[0036] Optionally, the width of the connecting portion is greater than the width of the extending portion.

[0037] The present invention also provides a battery assembly, comprising the above-mentioned solar cell.

[0038] The present invention also provides a photovoltaic system, comprising the above-mentioned battery assembly.

[0039] The beneficial effect achieved by the present invention is that the collected current is gathered and conducted out by setting the edge main grid and the edge pad point, and the connecting wire group connecting the edge main grid and the edge pad point. The connecting wire group includes a connecting conductor and a fine grid line, and the fine grid line is mounted on the hollow groove formed by the connecting conductor. The fine grid line is in contact with the doped layer, while the connecting conductor is not in physical contact with the doped layer. The fine grid line collects the carriers generated by the doped layer, reducing the carrier loss caused by the shielding of the connecting conductor. At the same time, the fine grid line and the connecting conductor are in contact only at both ends of the fine grid line, and the contact area is small, which can reduce the carrier recombination loss caused by the slurry recombination, and can also save the use of slurry during manufacturing, thereby reducing the production cost of solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a partial structural schematic diagram of the solar cell provided by the present invention.

[0041] Description of reference numerals:

[0042] 100, solar cell; 110, silicon substrate; 120, edge main grid; 121, connecting part; 122, extension part; 130, connecting wire group; 131, connecting conductor; 132, hollow groove; 133, fine grid line; 140, edge pad point; 150, first fine grid; 160, second fine grid. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0044] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0048] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0049] The present invention gathers and derives the collected current by setting an edge main grid and an edge pad point, and a connecting wire group connecting the edge main grid and the edge pad point. The connecting wire group includes a connecting conductor and a fine grid line, the fine grid line is arranged on a hollow groove formed by the connecting conductor, the fine grid line is in contact with the doped layer, and the connecting conductor is not in physical contact with the doped layer. The fine grid line collects the carriers generated by the doped layer, reducing the carrier loss caused by the shielding of the connecting conductor. At the same time, the fine grid line and the connecting conductor are only in contact at both ends of the fine grid line, and the contact area is small, which can reduce the carrier recombination loss caused by the slurry recombination, and can also save the slurry used during manufacturing, thereby reducing the production cost of the solar cell.

[0050] Embodiment 1

[0051] like Figure 1 As shown, this embodiment provides a solar cell 100, including:

[0052] A silicon substrate 110, on which a doping layer is stacked;

[0053] The edge main gate 120 is disposed at the edge of the silicon substrate 110 and extends along the first direction;

[0054] The edge pad point 140 is arranged corresponding to the edge main grid 120;

[0055] The connection line group 130 includes a connection conductor 131 and a thin gate line 133. The connection conductor 131 is not in physical contact with the doping layer and is used to connect the edge main gate 120 and the edge pad point 140. The connection conductor 131 extends along a second direction, and the second direction intersects the first direction.

[0056] The connecting conductor 131 forms at least one hollow groove 132 , and the fine gate line 133 is arranged at the hollow groove 132 . The fine gate line 133 is in physical contact with the doping layer.

[0057] The silicon substrate 110 is the basis of the solar cell 100, and generally includes a silicon substrate and various functional layers stacked on the silicon substrate, that is, the silicon substrate 110 is the other part of the solar cell 100 except for the metallized electrode pattern. The functional layer includes a doping layer, and the doping layer includes a p-type doping layer and an n-type doping layer. The p-type doping layer and the n-type doping layer can be arranged on one side or both sides of the silicon substrate to form a pn junction to generate a photovoltaic effect. When light shines on the solar cell 100, photons can excite electrons to jump from the valence band to the conduction band to form electron-hole pairs. These carriers are separated at the pn junction due to the electric field to generate current.

[0058] The edge main gate 120 is located at the edge of the silicon substrate 110 and extends along the first direction. The main gate is mainly used to gather and conduct the current collected from the fine gate (fine gate line 133 or other gate lines that are in physical contact with the doped layer). Therefore, the main gate needs to have good conductivity and sufficient cross-sectional area to carry a large current.

[0059] The edge pad point 140 is set corresponding to the edge main grid 120 and is placed close to the edge main grid 120. It can be understood that the edge pad point 140 is close to the edge main grid 120, that is, the distance between the edge pad point 140 and the edge main grid 120 is close. When other pad points are set on the solar cell 100, the distance between the edge pad point 140 and the edge main grid 120 is less than the distance between other pad points and the edge main grid 120. The edge pad point 140 is a conductor for connecting and outputting electricity. The number of edge pad points 140 can be one or more, which is specifically set according to the actual needs of the solar cell 100. When multiple edge pad points 140 are set corresponding to an edge main grid 120, the multiple edge pad points 140 are arranged along the first extension direction.

[0060] The connecting wire group 130 includes a composite structure composed of a connecting conductor 131 and a fine grid line 133, wherein the connecting conductor 131 maintains a certain non-physical contact with the doped layer. Specifically, an insulating medium may be provided at the non-physical contact position. The connecting conductor 131 connects the edge main grid 120 and the edge pad point 140. Since the connecting conductor 131, the edge main grid 120 and the edge pad point 140 are all conductors, the three are electrically connected. The connecting conductor 131 can guide the carriers (electrons or holes) collected by the edge main grid 120 to the edge pad point 140, and then lead them outward through the edge pad point 140. For example, the edge pad point 140 is connected to a welding strip, and the collected carriers are led out through the welding strip. The connecting conductor 131 extends along the second direction, and the second direction intersects with the first direction. This design can reduce shielding, ensure that more light can reach the doped layer, and improve the photoelectric conversion efficiency.

[0061] Specifically, the edge main grid 120 may extend along the longitudinal direction of the silicon substrate 110, and the connecting conductor 131 may extend along the lateral direction of the silicon substrate 110, that is, the first direction may be the longitudinal direction of the solar cell 100, and the second direction may be the lateral direction of the solar cell 100, and the two are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction may also be other directions, for example, the two may be diagonal directions of the silicon substrate 110, respectively, and are not specifically limited here.

[0062] A hollow groove 132 is formed on the connecting conductor 131, and a fine grid line 133 is arranged at the hollow groove 132 of the connecting conductor 131. The two ends of the fine grid line 133 are respectively connected to the groove walls on both sides of the hollow groove 132, and are in physical contact with the doping layer, so as to collect the carriers generated by the doping layer and reduce the carrier loss caused by the shielding of the connecting conductor 131. Specifically, the shape of the hollow groove 132 can be at least one of a rectangle, a circle, a trapezoid, a triangle, a fan, and an ellipse, which is not limited here.

[0063] At the contact position between the fine grid line 133 and the connecting conductor 131, carriers will be captured and recombined, resulting in recombination losses. The fine grid line 133 is in contact with the connecting conductor 131 at only two ends, and the contact area between the fine grid line 133 and the connecting conductor 131 is small, which can reduce the carrier recombination losses caused by the slurry recombination, and at the same time, can also save the slurry used during manufacturing, thereby reducing the production cost of the solar cell 100.

[0064] In this embodiment, the collected current is gathered and led out by setting the edge main grid 120 and the edge pad point 140, and the connection line group 130 connecting the edge main grid 120 and the edge pad point 140. The connection line group 130 includes a connection conductor 131 and a fine grid line 133. The fine grid line 133 is mounted on the hollow groove 132 formed by the connection conductor 131. The fine grid line 133 is in contact with the doped layer, while the connection conductor 131 is not in contact with the doped layer. The fine grid line 133 collects the carriers generated by the doped layer, reducing the carrier loss caused by the shielding of the connection conductor 131. At the same time, the fine grid line 133 and the connection conductor 131 are in contact only at both ends of the fine grid line 133, and the contact area is small, which can reduce the carrier recombination loss caused by the slurry recombination, and can also save the use of slurry during manufacturing, thereby reducing the production cost of the solar cell 100.

[0065] In one embodiment, at least one thin grid line 133 is arranged at the hollow groove 132 .

[0066] The number of fine grid lines 133 set up at a hollow groove 132 can be one or more. Setting only one fine grid line 133 can reduce the shielding area and improve the photoelectric conversion efficiency of the battery. When multiple fine grid lines 133 are set, not only can the carriers be better collected, but also it can be used as a redundant design. When a fine grid line 133 is broken, other fine grid lines 133 can continue to collect current with better stability. When multiple fine grids are set, the multiple fine grids can be set in parallel or at a certain angle, which is not limited here.

[0067] In one embodiment, the fine gate lines 133 extend along the second direction.

[0068] The connecting conductor 131 extends along the second direction, and the extending direction of the thin grid line 133 is consistent with the extending direction of the connecting conductor 131. This arrangement helps to uniformly transmit the current, reduce the local resistance inside the battery, and improve the overall current collection efficiency.

[0069] Embodiment 2

[0070] In one embodiment, along the second direction, the total length of the thin gate line 133 is 10% to 90% of the total length of the connecting conductor 131 .

[0071] The connecting conductor 131 extends along the second direction, and the total length of the connecting conductor 131 along the second direction refers to the length of the connecting conductor 131 between the edge main grid 120 and the edge pad point 140. The total length of the fine grid line 133 along the second direction is, that is, the projection length of the fine grid line 133 in the second direction. It can be understood that when multiple fine grid lines 133 are provided, if the projections of multiple fine grid lines 133 in the second direction overlap, the length of the overlapping portion is only calculated once.

[0072] The total length of the fine grid lines 133 is 10% to 90% of the total length of the connecting conductor 131. For example, assuming that the total length of the connecting conductor 131 is 10 mm, the total length of the fine grid lines 133 can be 1 mm to 9 mm. This ensures that the fine grid lines 133 can effectively transmit current without excessively blocking the silicon substrate 110 and affecting the light absorption efficiency. By reasonably designing the length of the fine grid lines 133, damage caused by excessive accumulation of materials can be avoided, thereby improving the long-term reliability of the battery.

[0073] In one embodiment, along the second direction, the total length of the thin gate line 133 is 50% to 90% of the total length of the connecting conductor 131 .

[0074] The total length of the fine grid lines 133 along the second direction is 50% to 90% of the total length of the connecting conductor 131. For example, assuming that the total length of the connecting conductor 131 is 10 mm, the total length of the fine grid lines 133 can be 5 mm to 9 mm. A higher length ratio of the fine grid lines 133 can maximize the collection efficiency of carriers and improve the photoelectric conversion efficiency of the battery. Compared with full-length coverage, this method can reduce the amount of slurry used and reduce costs.

[0075] Embodiment 3

[0076] In one embodiment, at least one hollow groove 132 is provided, and the hollow groove 132 extends along the second direction.

[0077] The extension direction of the hollow groove 132 is consistent with the extension direction of the connecting conductor 131, which reduces the shielding of the silicon substrate 110 by the connecting conductor 131 and improves the light transmittance, so that more light can pass through the hollow groove 132 and irradiate the silicon substrate 110, thereby improving the photoelectric conversion efficiency of the battery.

[0078] In one embodiment, the total area of ​​the hollow grooves 132 accounts for 1% to 50% of the total area of ​​the connecting conductor 131 .

[0079] It can be understood that the "area" in this embodiment refers to the area of ​​the side of the connecting conductor 131 facing away from the silicon substrate. Usually, the thickness of the connecting conductor 131 is relatively thin. If the hollow groove 132 is set to occupy too large a proportion, the portion of the connecting conductor 131 used to transmit current becomes smaller, which is not conducive to current transmission. The total area of ​​the hollow groove 132 is the sum of the areas of each hollow groove, accounting for 1% to 50% of the total area of ​​the connecting conductor 131, which is conducive to ensuring that the connecting conductor 131 retains enough conductive parts for transmitting current.

[0080] In one embodiment, a plurality of hollow grooves 132 are provided.

[0081] The plurality of hollow grooves 132 can further reduce the shielding of the silicon substrate 110 by the connecting conductor 131, thereby improving the light absorption efficiency of the cell and reducing the use of connecting materials and costs.

[0082] Specifically, the hollow grooves 132 are arranged along the same straight line along the second direction, that is, the center lines of the plurality of hollow grooves 132 along the second direction coincide with each other. The hollow grooves 132 are arranged along the same straight line, which can ensure more uniform carrier collection and reduce the impact of local non-uniformity on battery performance. At the same time, the hollow grooves 132 arranged in a straight line can be easily realized by processes such as screen printing, reducing the difficulty of manufacturing.

[0083] Alternatively, at least some of the hollow grooves 132 may be arranged in a staggered manner along the second direction, that is, at least some of the hollow grooves 132 may be staggered along the center line of the second direction. Specifically, some of the hollow grooves 132 may be arranged along the same straight line, some of the hollow grooves 132 may be arranged in a staggered manner, or all of the hollow grooves 132 may be arranged in a staggered manner. Hollow grooves 132 in which the hollow grooves 132 are arranged in a staggered manner can avoid the fine grid lines 133 from being concentrated in a certain area, reduce the impact of local shading on battery performance, better utilize light energy, and improve photovoltaic conversion efficiency.

[0084] In one embodiment, along the second direction, distances between adjacent hollow grooves 132 are equal.

[0085] If the position on any hollow groove 132 closest to the adjacent hollow groove 132 is taken as the vertex, the distance between the vertices of two adjacent hollow grooves 132 is the distance between the two hollow grooves 132. The equal distance ensures that the hollow grooves 132 and the thin grid lines 133 are evenly distributed on the connecting conductor 131, thereby improving the uniformity of carrier collection.

[0086] In one embodiment, along the second direction, distances between at least some adjacent hollow grooves 132 are unequal.

[0087] The distances between all adjacent hollow grooves 132 may be unequal. For example, four hollow grooves 132 are provided, and the distance between the first hollow groove 132 and the second hollow groove 132 is 50 μm, the distance between the second hollow groove 132 and the third hollow groove 132 is 60 μm, and the distance between the third hollow groove 132 and the fourth hollow groove 132 is 70 μm. Alternatively, the distances between some adjacent hollow grooves 132 are equal, and the distances between some adjacent hollow grooves 132 are unequal. For example, the distance between the first hollow groove 132 and the second hollow groove 132 is 50 μm, the distance between the second hollow groove 132 and the third hollow groove 132 is 50 μm, and the distance between the third hollow groove 132 and the fourth hollow groove 132 is 70 μm.

[0088] The unequal spacing design can optimize the distribution of the fine grid lines 133 and reduce local shading according to the light intensity and battery design requirements.

[0089] In one embodiment, along the second direction, the fine gates are collinear.

[0090] When a plurality of hollow grooves 132 are formed on the connecting conductor 131, the fine grid lines 133 arranged on the hollow grooves 132 are distributed along the same straight line. The collinear arrangement can collect carriers in a concentrated manner and reduce the influence of dispersion on battery performance. At the same time, the collinear arrangement of the fine grid lines 133 can simplify the design and manufacturing process and improve production efficiency.

[0091] In one embodiment, the fine grids are staggered along the second direction.

[0092] When a plurality of hollow grooves 132 are formed on the connecting conductor 131, at least some of the fine grid lines 133 arranged on each hollow groove 132 are not distributed along the same straight line. Specifically, all the fine grid lines 133 may not be distributed along the same straight line, that is, all the fine grid lines 133 are not collinear; or some of the fine grid lines 133 may be distributed along the same straight line, and some of the fine grid lines 133 may not be along the same straight line. For example, four hollow grooves 132 are provided, and a fine grid line 133 is arranged on each hollow groove 132, wherein three fine grid lines 133 are distributed along the same straight line, and one fine grid line 133 has a certain spacing or forms a certain angle with the three collinear fine grid lines 133.

[0093] In one embodiment, along the second direction, at least one thin grid line 133 is disposed at the center of the hollow groove 132 .

[0094] That is, at least one thin grid line 133 is arranged at a position overlapping with the center line of the hollow groove 132. At the center position, the thin grid line 133 is at an equal distance from the walls of the hollow groove 132 on both sides, ensuring that the thin grid line 133 is evenly distributed in the groove to avoid local overheating. At the center position, the thin grid line 133 can also provide an optimal contact point, reduce contact resistance, and improve carrier transmission efficiency.

[0095] In one embodiment, along the second direction, at least one thin grid line 133 is disposed at an edge of the hollow groove 132 .

[0096] That is, at least one thin grid line 133 is set at a position that does not overlap with the center line of the hollow groove 132, that is, the thin grid line 133 deviates from the center line position of the hollow groove 132, and can be a certain distance or angle from the center line position. The thin grid line 133 at the edge position can optimize the illumination area and reduce the impact of shading on battery performance.

[0097] Embodiment 4

[0098] In one embodiment, the width of the connection conductor 131 is 100-400 μm.

[0099] Since the connection conductor 131 extends along the second direction, the width of the connection conductor 131 refers to the distance between two opposite sides of the connection conductor 131 perpendicular to the second extending direction.

[0100] The wider the width of the connection conductor 131, the wider the channel width provided for carriers to pass through, the smaller the resistance, and the more conducive to the transmission of carriers. However, the wider the width of the connection conductor 131, the greater the shielding of the silicon substrate 110. Through experimental verification, when the width of the connection conductor 131 is between 100 and 400 μm, it can be ensured that the connection conductor 131 has good conductivity, reduces current transmission loss, and at the same time, will not have a significant impact on the photoelectric conversion efficiency of the solar cell 100.

[0101] Specifically, the width of the connecting conductor 131 can be 100μm, 120μm, 140μm, 160μm, 180μm, 200μm, 220μm, 240μm, 260μm, 280μm, 300μm, 320μm, 340μm, 350μm, 370μm, 380μm, 385μm, 390μm, 400μm, or other values ​​between 100 and 400μm, which are not limited here.

[0102] In one embodiment, the width of the connecting conductor 131 is 200-300 μm. Specifically, when the width of the connecting conductor 131 is between 200 and 300 μm, the conductivity and the shielding of the silicon substrate 110 can be better balanced, the overall performance of the battery can be improved, and while ensuring the performance, excessive shielding of the silicon substrate 110 can be avoided to affect the photoelectric conversion efficiency.

[0103] Embodiment 5

[0104] In one embodiment, the edge bus gate 120 includes a connection portion 121 contacting the connection conductor 131 and extension portions 122 extending along two ends of the connection portion 121 . The width of the connection conductor 131 is 1 to 5 times the width of the connection portion 121 .

[0105] Since the connection conductor 131 extends along the second direction, the width of the connection conductor 131 refers to the distance between two opposite sides of the connection conductor 131 perpendicular to the second extension direction. While the edge busbar 120 extends along the first direction, the width of the edge busbar 120 refers to the distance between two opposite sides of the edge busbar 120 perpendicular to the first extension direction.

[0106] The edge main grid 120 is in contact with the connection conductor 131 at the connection portion 121 of the connection conductor 131. At the connection portion 121, the connection conductor 131 transfers the carriers collected by the edge pad point 140 to the edge main grid 120. A wider connection conductor 131 can reduce resistance, which is beneficial to the transmission of carriers on the connection conductor 131. At the same time, the width of the connection portion 121 is 0.2 to 1 times the width of the connection conductor 131, so as to avoid the connection portion 121 being too narrow to allow the carriers transmitted from the connection conductor 131 to pass smoothly, thereby affecting the battery transmission efficiency.

[0107] The width of the connection conductor 131 is 1 to 5 times the width of the connection portion 121 to optimize current collection and reduce current loss. For example, the width of the connection portion 121 is 100 μm, and the width of the connection conductor 131 is 400 μm (4 times).

[0108] In one embodiment, the width of the connection conductor 131 is 1 to 3 times the width of the connection portion 121 .

[0109] Further optimizing the width of the connection conductor 131 to be within the range of 1 to 3 times the width of the connection portion 121 can further optimize the conductivity and avoid a large difference in width between the connection conductor 131 and the connection portion 121, which affects the transmission efficiency.

[0110] For example, the width of the connection portion 121 is 150 μm, and the width of the connection conductor 131 is 300 μm (twice).

[0111] Embodiment 6

[0112] In one embodiment, the edge busbar 120 includes a connection portion 121 contacting the connection conductor 131 and extension portions 122 extending along both ends of the connection portion 121 . The cross-sectional area of ​​the connection conductor 131 is 1 to 5 times the cross-sectional area of ​​the connection portion 121 .

[0113] Since the connection conductor 131 extends along the second direction, the cross section of the connection conductor 131 is cut perpendicularly to the second extension direction. While the edge busbar 120 extends along the first direction, the cross section of the edge busbar 120 is cut perpendicularly to the first extension direction.

[0114] The edge main grid 120 is in contact with the connection conductor 131 at the connection portion 121 of the connection conductor 131. At the connection portion 121, the connection conductor 131 transfers the carriers collected by the edge pad point 140 to the edge main grid 120. The connection conductor 131 with a larger cross-section can reduce the resistance, which is beneficial to the transmission of carriers on the connection conductor 131. At the same time, the cross-sectional area of ​​the connection portion 121 is 0.2 to 1 times the cross-sectional area of ​​the connection conductor 131, so as to avoid the connection portion 121 having a cross-sectional area that is too small to allow the carriers transmitted from the connection conductor 131 to pass smoothly, thereby affecting the battery transmission efficiency.

[0115] The cross-sectional area of ​​the connection conductor 131 is 1 to 5 times the cross-sectional area of ​​the connection portion 121 to optimize current collection and reduce current loss. For example, the cross-sectional area of ​​the connection portion 121 is 100 μm, and the cross-sectional area of ​​the connection conductor 131 is 400 μm (4 times).

[0116] In one embodiment, the cross-sectional area of ​​the connection conductor 131 is 1 to 3 times the cross-sectional area of ​​the connection portion 121 .

[0117] Further optimizing the cross-sectional area of ​​the connection conductor 131 to be within the range of 1 to 3 times the cross-sectional area of ​​the connection portion 121 can further optimize the conductivity and avoid a large difference in the cross-sectional areas of the connection conductor 131 and the connection portion 121, which affects the transmission efficiency.

[0118] For example, the cross-sectional area of ​​the connection portion 121 is 150 μm, and the cross-sectional area of ​​the connection conductor 131 is 300 μm (twice).

[0119] Embodiment 7

[0120] like Figure 1 As shown, in one embodiment, a plurality of first fine gates 150 and a plurality of second fine gates 160 are alternately arranged along a first direction on a silicon substrate 110, and edge main gates 120 and edge pad points 140 are respectively arranged on two opposite edges of the silicon substrate 110, the first fine gates 150 are connected to the edge main gates 120 and edge pad points 140 on one side, and the second fine gates 160 are connected to the edge main gates 120 and edge pad points 140 on the other side, wherein the first fine gates 150 and the second fine gates 160 have different polarities.

[0121] It can be understood that a p-type region and an n-type region are provided on the silicon substrate 110, and the p-type region and the n-type region form regions with different electrical characteristics, supporting the formation of a PN junction and the separation of carriers. The first fine gate 150 and the second fine gate 160 are respectively provided in regions of two polarities. Specifically, the first fine gate 150 may be provided in the p-type region, and the second fine gate 160 may be provided in the n-type region, or specifically, the first fine gate 150 may be provided in the n-type region, and the second fine gate 160 may be provided in the p-type region.

[0122] The two opposite sides of the silicon substrate 110 are respectively a first side and a second side, and the edge main gate 120 and the edge pad point 140 corresponding to the edge main gate 120 are respectively arranged on the two side edges. Specifically, the first fine gate 150 and the second fine gate 160 can be connected to the edge pad point 140 through a wire, and the wire used for connection is not in physical contact with the doping layer.

[0123] Taking the first fine gate 150 being arranged in the p-type region and the second fine gate 160 being arranged in the n-type region as an example: the first fine gate 150 collects holes generated in the p-type region, the first fine gate 150 is connected with the edge main gate 120 and the edge pad point 140 on the first side, and the holes collected by the first fine gate 150 are transferred to the edge main gate 120 and connected with the load through the edge main gate 120. Specifically, part of the first fine gate 150 is directly connected with the edge main gate 120 on the first side, and part of the first fine gate 150 is connected with the edge pad point 140 and connected with the edge main gate 120 on the first side through the connecting line group 130. The second fine gate 160 collects electron holes generated in the n-type region, the second fine gate 160 is connected with the edge main gate 120 and the edge pad point 140 on the second side, and the electrons collected by the second fine gate 160 are transferred to the edge main gate 120 and connected with the load through the edge main gate 120. Specifically, part of the second fine gate 160 is directly connected to the edge main gate 120 on the second side, and part of the second fine gate 160 is connected to the edge Pad point 140 and communicates with the edge main gate 120 on the second side through the connection line group 130 .

[0124] In one embodiment, first regions and second regions are alternately arranged along a first direction on the silicon substrate 110 , and the first regions and the second regions have different polarities; the first fine gates 150 are arranged in the first regions, and the second fine gates 160 are arranged in the second regions.

[0125] Specifically, the silicon base 110 includes a silicon substrate and a doping layer, and the doping layer is arranged on the silicon substrate. The doping layer includes a first doping layer and a second doping layer. The first doping layer is arranged in the first region, and the second doping layer is arranged in the second region. The first region and the second region are arranged alternately along the first direction, that is, the first doping layer and the second doping layer are alternately arranged along the first direction on the silicon substrate. The first doping layer and the second doping layer have different polarities, and the first doping layer may be a P-type doping layer and the second doping layer may be an N-type doping layer, or the first doping layer may be an N-type doping layer and the second doping layer may be a P-type doping layer. The first polarity doping layer and the second polarity doping layer form regions with different electrical characteristics, supporting the formation of PN junctions and the separation of carriers.

[0126] The first fine gate 150 is arranged in the first region, in ohmic contact with the first doped layer, and collects carriers generated in the first region. The second fine gate 160 is arranged in the second region, in ohmic contact with the second doped layer, and collects carriers generated in the second region. Alternating the first region and the second region can ensure uniform distribution of the fine gate lines 133 on the silicon substrate 110, and improve the uniformity of carrier collection.

[0127] It can be understood that the first area and the second area are arranged alternately, that is, the first area and the second area are arranged on the same piece of the silicon substrate 110, usually, they are arranged on the backlight surface of the silicon substrate 110. The first fine grid 150 and the second fine grid 160 are arranged corresponding to the first area and the second area respectively, and the first fine grid 150 and the second fine grid 160 are arranged on the backlight surface of the silicon substrate 110. The light-facing surface of the silicon substrate 110 is not blocked by the fine grid, so the light absorption area can be maximized, the shadow loss can be reduced, and the photoelectric conversion efficiency of the battery can be significantly improved.

[0128] Embodiment 8

[0129] In one embodiment, the connection conductor 131 is a copper conductor or an aluminum conductor, and the fine grid line 133 is a silver fine grid line.

[0130] For example, the connection conductor 131 is a 250 μm wide copper conductor, and the fine grid line 133 is a 50 μm wide silver fine grid line 133. The connection conductor 131 mainly plays the role of transmitting carriers. Copper and aluminum have good electrical conductivity, which can reduce the resistance on the connection conductor 131 and improve the current transmission efficiency. At the same time, the cost of copper and aluminum is low, which reduces the overall manufacturing cost.

[0131] The fine grid lines 133 need to be in contact with the doped layer, and in addition to having excellent conductivity, they also need to have good contact performance. Silver fine grid lines have excellent conductivity and contact performance, which can improve the reliability of the battery.

[0132] Different conductive materials are selected according to the different functions of the link conductor and the fine grid line 133, which saves the use of silver paste and reduces the production cost.

[0133] Embodiment 9

[0134] In one embodiment, the width of the connecting portion 121 is greater than the width of the extending portion 122 .

[0135] The connecting portion 121 is used to connect to the connecting conductor 131 and receive the carriers transmitted by the connecting conductor 131, that is, the carriers transmitted by the connecting conductor 131 are collected at the connecting portion 121. The wider connecting portion 121 can optimize the collection of carriers and reduce the loss during the current transmission process. The width of the extension portion 122 is smaller than the width of the connecting portion 121, and the narrower extension portion 122 can reduce the amount of materials used and reduce costs.

[0136] Embodiment 10

[0137] This embodiment provides a battery assembly, including the solar cell 100 in the above embodiment.

[0138] The battery module may include multiple solar cells 100. The multiple solar cells 100 in the battery module may be connected in series in sequence to form a battery string. The battery strings may be connected in series, in parallel, or in a combination of series and parallel to achieve current bus output. For example, the connection between the individual battery cells may be achieved by welding welding strips, and the connection between the individual battery strings may be achieved by bus bars.

[0139] The battery assembly may also include a metal frame, a back plate, photovoltaic glass and an adhesive film (not shown in the figure). The adhesive film may be filled between the light-facing surface and the photovoltaic glass, the backlight surface and the back plate of the solar cell 100, and the adjacent cells, etc. As a filler, it may be a transparent colloid with good light transmission and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0140] Photovoltaic glass can cover the adhesive film on the light-facing surface of the solar cell 100. The photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the solar cell 100 without affecting the efficiency of the solar cell 100 as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the solar cell 100 together, and the presence of the adhesive film can seal and insulate the solar cell 100 and prevent water and moisture.

[0141] The backplane can be attached to the adhesive film on the backlight surface of the solar cell 100. The backplane can protect and support the solar cell 100 and has reliable insulation, water resistance and aging resistance. There are multiple options for the backplane, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to specific circumstances and is not limited here. The whole composed of the backplane, solar cell 100, adhesive film and photovoltaic glass can be set on a metal frame. The metal frame serves as the main external support structure of the entire battery assembly and can stably support and install the battery assembly. For example, the battery assembly can be installed at the required location through the metal frame.

[0142] The beneficial effects of the battery assembly of this embodiment are equivalent to the beneficial effects of the above-mentioned solar cell 100, and will not be described in detail here.

[0143] Embodiment 10

[0144] The embodiment provides a photovoltaic assembly, comprising the battery assembly in the above embodiment.

[0145] Photovoltaic systems can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of photovoltaic systems are not limited to this, that is to say, photovoltaic systems can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple battery components. For example, multiple battery components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid. After that, it is connected to the mains network to realize solar power supply.

[0146] The beneficial effects of the photovoltaic system of this embodiment are equivalent to the beneficial effects of the above-mentioned battery assembly, and will not be described in detail here.

[0147] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A solar cell, characterized in that: include: a silicon substrate including a doped layer; An edge main gate is arranged at an edge position of the silicon substrate and extends along a first direction; Edge Pad points, arranged corresponding to the edge main grid; A connection line group, comprising a connection conductor and a thin gate line, wherein the connection conductor is not in physical contact with the doped layer and is used to connect the edge main gate and the edge pad point, and the connection conductor extends along a second direction, and the second direction intersects the first direction; The connecting conductor forms at least one hollow groove, the fine gate line is arranged at the hollow groove, and the fine gate line is in physical contact with the doping layer.

2. The solar cell according to claim 1, characterized in that At least one thin grid line is arranged at each of the hollow grooves.

3. The solar cell according to claim 1, characterized in that The fine gate lines extend along the second direction.

4. The solar cell according to claim 1, characterized in that Along the second direction, the total length of the thin gate lines is 10% to 90% of the total length of the connecting conductors.

5. The solar cell according to claim 4, characterized in that: Along the second direction, the total length of the thin gate lines is 50% to 90% of the total length of the connecting conductors.

6. The solar cell according to claim 1 or 2, characterized in that: At least one hollow groove is provided, and the hollow groove extends along the second direction.

7. The solar cell according to claim 6, characterized in that The hollow grooves are arranged in plurality.

8. The solar cell according to claim 7, characterized in that Along the second direction, the hollow grooves are arranged along the same straight line.

9. The solar cell according to claim 7, characterized in that: Along the second direction, at least some of the hollow grooves are arranged in a staggered manner.

10. The solar cell according to any one of claims 7 to 9, characterized in that: Along the second direction, distances between adjacent hollow grooves are equal.

11. The solar cell according to any one of claims 7 to 9, characterized in that: Along the second direction, distances between at least some adjacent hollow grooves are unequal.

12. The solar cell according to claim 2, characterized in that: The hollow groove is at least one of a rectangular, circular, trapezoidal, triangular, fan-shaped, and elliptical shape.

13. The solar cell according to claim 7, characterized in that: Along the second direction, the fine gates are collinear.

14. The solar cell according to claim 7, characterized in that: Along the second direction, at least some of the fine grids are staggered.

15. The solar cell according to claim 7, characterized in that: Along the second direction, at least one of the thin grid lines is placed at a central position of the hollow groove.

16. The solar cell according to claim 7, characterized in that: Along the second direction, at least one of the thin grid lines is placed at an edge of the hollow groove.

17. The solar cell according to claim 1, characterized in that: The total area of ​​the hollow grooves accounts for 1% to 50% of the total area of ​​the connecting conductor 131 .

18. The solar cell according to claim 1, characterized in that: The width of the connecting conductor is 100-400 μm.

19. The solar cell according to claim 18, characterized in that The width of the connecting conductor is 200-300 μm.

20. The solar cell according to claim 1, characterized in that The edge main grid includes a connection portion contacting the connection conductor and extension portions extending along two ends of the connection portion. The width of the connection conductor is 1 to 5 times the width of the connection portion.

21. The solar cell according to claim 20, characterized in that The width of the connecting conductor is 1 to 3 times the width of the connecting portion.

22. The solar cell according to claim 1, characterized in that The edge main grid includes a connection portion in contact with the connection conductor and extension portions extending along two ends of the connection portion. The cross-sectional area of ​​the connection conductor is 1 to 5 times the cross-sectional area of ​​the connection portion.

23. The solar cell according to claim 22, characterized in that The cross-sectional area of ​​the connecting conductor is 1 to 3 times the cross-sectional area of ​​the connecting portion.

24. The solar cell according to claim 1, characterized in that A plurality of first fine gates and a plurality of second fine gates are alternately arranged along the first direction on the silicon substrate, and the edge main gate and the edge Pad point are respectively set on the two opposite edges of the silicon substrate, the first fine gate is connected to the edge main gate and the edge Pad point on one side, and the second fine gate is connected to the edge main gate and the edge Pad point on the other side, wherein the first fine gate and the second fine gate have different properties.

25. The solar cell according to claim 24, characterized in that A first region and a second region are alternately arranged on the silicon substrate along the first direction, and the first region and the second region have different polarities; The first fine gate is disposed in the first region, and the second fine gate is disposed in the second region.

26. The solar cell according to claim 1, characterized in that The connecting conductor is a copper conductor or an aluminum conductor, and the fine grid wire is a silver fine grid wire.

27. The solar cell according to any one of claims 20 to 23, characterized in that: The width of the connecting portion is greater than the width of the extending portion.

28. A battery assembly, characterized in that: A solar cell comprising any one of claims 1 to 27.

29. A photovoltaic system, characterized in that: A battery assembly comprising the battery assembly of claim 28.

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